No common name

Distaplia cylindrica

ORDER Enterogona

FAMILY Holozoidae

TAXONOMY

Holozoa cylindrica Lesson, 1830, Magellan Strait.

OTHER COMMON NAMES None known.

PHYSICAL CHARACTERISTICS

Colonial species with very long, sausage-shaped colonies. This species is the largest known ascidian; the colonies may reach 23 ft (7 m) in length and 3 in (8 cm) in diameter. Colony is white or yellowish and soft to the touch; it is attached by one end to rocks and grows vertically. As for most ascidians, individual zooids are small and located only in the superficial layer of the colony, where they form numerous small, oval systems.

DISTRIBUTION

Completely circumpolar in the Antarctic.

HABITAT

Rocky bottoms at depths from 66 to 1,444 ft (20-440 m). Sometimes colonies are found floating on the surface, but such detached colonies always have degenerated zooids.

BEHAVIOR

Sessile, attached, immobile species.

FEEDING ECOLOGY AND DIET Filter feeder.

REPRODUCTIVE BIOLOGY

Hermaphrodite, but zooids in distinct parts of the colony may have different sexual status: some zooids have better developed male gonads, whereas others have better developed female go-nads. Zooids with well-developed gonads are found in colonies in December and January; fully developed tailed larvae appear from January to April. Larvae are incubated in brood pooches within parent colony.

CONSERVATION STATUS Not listed by the IUCN.

SIGNIFICANCE TO HUMANS None known. ♦

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